Module 04 Homework Assignment · Use the information presented in the module folder along with your readings from the textbook to answer the following question

s. 1. Describe the different morphological types of viruses and give examples of each type:

a. Helical b. Icosahedral c. Complex 2. Compare and contrast the multiplication of bacteriophages versus the multiplication of animal viruses:

3. Describe how arthropods can act as mechanical vectors and biological vectors:

4. Describe five (5) characteristics of fungi and how they differ from other microorganisms:

5. Describe common characteristic of protozoans (protists). Name three (3) protozoans that are human parasites:

6. What are helminths? Name and describe three (3) that can cause problems in humans: Confidential & Proprietary © Rasmussen 2017

 

SOLUTIONS

1. Different morphological types of viruses are:

a. Helical: These viruses have a helical structure with a capsid made of protein subunits arranged in a helix. Examples include tobacco mosaic virus and influenza virus.

b. Icosahedral: These viruses have a spherical shape with a capsid made up of 20 triangular faces. Examples include rhinovirus, poliovirus, and herpesvirus.

c. Complex: These viruses have a complex structure with a combination of helical and icosahedral components. Examples include bacteriophages, such as T4 phage.

2. Bacteriophages and animal viruses differ in their multiplication process. Bacteriophages infect bacteria, and their multiplication process involves attachment, penetration, replication, assembly, and release. Animal viruses infect animal cells, and their multiplication process involves attachment, penetration, uncoating, replication, assembly, and release.

3. Arthropods can act as mechanical vectors by carrying pathogens on their body parts or in their digestive system. Arthropods can also act as biological vectors by transmitting pathogens through their bites, feces, or saliva. For example, mosquitoes act as biological vectors for malaria, while flies act as mechanical vectors for diseases such as salmonellosis.

4. Five characteristics of fungi are:

• Fungi are eukaryotic organisms.
• Fungi are heterotrophs that obtain nutrients by absorbing organic matter from their surroundings.
• Fungi reproduce through spores.
• Fungi have cell walls made of chitin.
• Fungi can be either unicellular (yeasts) or multicellular (mushrooms).

Fungi differ from other microorganisms in their cell wall composition, mode of nutrition, and reproductive strategies.

5. Common characteristics of protozoans (protists) include:

• Protozoans are unicellular eukaryotic organisms.
• Protozoans are heterotrophs that can be either free-living or parasitic.
• Protozoans reproduce asexually or sexually through binary fission, budding, or conjugation.

Three protozoans that are human parasites are Plasmodium (causes malaria), Giardia (causes giardiasis), and Trypanosoma (causes sleeping sickness).

6. Helminths are parasitic worms that can infect humans. Three helminths that can cause problems in humans are:

• Ascaris lumbricoides: a roundworm that can cause intestinal obstruction and malnutrition.
• Taenia saginata: a tapeworm that can cause intestinal infections and weight loss.
• Schistosoma mansoni: a fluke worm that can cause liver and intestinal damage.